It has long been known in tile disposable absorbent bandage art that it is extremely desirable to construct absorptive devices such as disposable diapers, catamenial pads, sanitary napkins, incontinent briefs, and the like, which present a dry surface feel to the user to improve wearing comfort and to minimize the development of undesirable skin conditions due to prolonged exposure to moisture absorbed within the bandage.
One viable prior art solution to the aforementioned problem is disclosed in commonly assigned U.S. Pat. No. 4,342,314 issued to Radel, et al. on Aug. 3, 1982 and hereby incorporated herein by reference. Radel, et al. discloses an absorbent bandage with a wearer-contacting topsheet comprising a resilient, macroscopically expanded, three-dimensional plastic web exhibiting a combination of fiber-like and plastic properties. In a preferred embodiment, the macroscopically expanded, three-dimensional, plastic web topsheet disclosed in Radel, et al. exhibits a fine scale three-dimensional microstructure comprising a regulated continuum of capillary networks originating in and extending from one surface of the web and terminating in the form of apertures in the opposite surface thereof to promote rapid fluid transport. The web's fiber-like appearance is comprised of a continuum of fiber-like elements, the opposed ends of each of the fiber-like elements are interconnected to at least one other of the fiber-like elements.
A typical capillary network in the Radel, et al. structure comprises an uppermost capillary opening or aperture formed by a multiplicity of fiber-like elements interconnected to one another in the uppermost plane of the web. Each of the fiber-like elements exhibits a substantially uniform U-shaped cross-section along its length. The cross-section of the fiber-like element comprises a base portion located in the wearer-contacting plane and a sidewall portion joined to each edge of the base portion, tile sidewall portions extend generally in the direction of the absorbent pad-contacting surface of the web. The sidewall portions which intersect one another are joined to one another intermediate the wearing contacting surface and the absorbent pad contacting surface of the web, thereby forming a capillary network interconnecting the opposed surface of the web.
A topsheet of the type generally disclosed by Radel, et al. is highly effective in promoting rapid fluid transfer from the first, wearer-contacting surface to the second, absorbent pad-contacting surface of the topsheet. Accordingly, topsheets of this type have enjoyed widespread commercial success on catamenial pads due to their clean and dry appearance in use when contrasted to conventional nonwoven fibrous topsheets. While an absorbent article having a topsheet of the type disclosed in Radel, et al. is highly effective in promoting rapid transfer of bodily fluids from the first, wearer-contacting surface to the second, absorbent pad-contacting surface, the degree of masking of bodily fluids, e.g., menses, retained within the absorbent core is dependent upon the size of the capillary networks. As the size of the capillary networks decrease the amount of masking provided by the topsheet increases. However, if the capillary networks are too small bodily fluids are not able to pass through the topsheet into the absorbent core thereby exposing the skin to moisture.
Accordingly, it is an object of tile present invention to provide an absorbent article with a topsheet or multiple topsheets having superior fluid handling properties while providing increased masking of bodily fluids retained within the absorbent core.